This invention relates to a system for providing thermal resistance or protection for hypersonic aerospace vehicles and is particularly directed to the production of a combined integral structure and thermal protection system (IS/TPS) for such vehicles.
In the design of thermal protection systems for aerospace vehicles, such system should not transfer excessive heat to the basic vehicle structure, should have low weight, and should produce low thermal stresses. Current thermal protection system concepts employ multitudes of ceramic tiles as reusable surface insulation to accommodate thermal expansion differences with the structure and multitudes of joints resulting in considerable undesirable weight. Such tiles have the further disadvantages of being weak, brittle, and subject to surface cracking, and being labor intensive, both for production and for maintenance.
Various thermal protection systems have been developed in the prior art to overcome these problems. Thus, U.S. Pat. No. 4,344,591 is directed to a multiwall thermal protection system to replace the tile system of the prior art. This patent employs a panel concept with a hard external surface. In one embodiment, the multiwall panels are formed of alternate layers of dimpled and flat titanium alloy foil sheets and beaded scarfed edge seals. An additional embodiment employs an intermediate fibrous insulation for the sandwich panel, and a third embodiment employs a silicide-coated columbium waffle as the outer panel skin and fibrous layered intermediate protection. The panels of this patent are attached to load-bearing channels which are a part of the airframe by means of clips that will deflect to compensate thermal loads.
Examples of other thermal insulation and protection systems are disclosed in U.S. Pat. Nos. 3,177,811; 3,793,861; 3,955,034; 4,173,187; 3,236,476; 3,920,339; and 4,112,179.
It is accordingly an object of the present invention to provide an improved novel thermal protection system for hypersonic vehicles.
Another object of the invention is to provide a durable, light-weight and reusable thermal protection and structure system for high-speed aerospace vehicles.
A further object of the invention is the provision of an improved cost-effective thermal protection or insulation system for high-speed aerospace vehicles, which is readily constructed and maintained, and is formed integral with an airframe component, such as the fuselage, wing or vertical tail of the aerospace vehicle.